I have made a human in blender and i want to upload to roblox and make it a model and make it a model do i need to split every body part like foot, arm and upload one by one?
Yes you will as there is no other ways to import meshes into Roblox.
If this helped please accept this answer.
I don’t believe you need to export-import all files individually. The mesh splitting update allows you to import and export whole meshes and have them split in studio (not sure about which extensions are required, I’m sure the thread has the info). Moreover you can bulk import meshes if you do end up exporting meshes individually from your software.